Compressed imagery

Using ImageOptim for Mac
Added humans.txt
Further image compression
Front-end changes: -bootstrap, +html5, -css_browser_selector

Removed bootstrap from core CSS.
Added properties to scaleconf2013.css that were being used in
bootstrap.css
Moved to an HTML5 doctype.
Fixed malformed HTML in page.html
Moved the GA script to the bottom of the page.
Added Russel and Stefano to humans.txt
Merge branch 'master' into gh-pages